I won’t need the second floor piece so I filled in all the floor slots cut into the interior sides of the shell walls with quick dry spackle.Once the spackle was dry, I sanded it smoothe and painted the shell walls with a water-based, white pigmented primer by Zinsser.The white pigment in the primer will ensure that I get an even distribution of the paint color when the walls are painted as well as protect the life of the project from changes in climate.